TA recently told me they can no longer get the Stock Lite Weight wrist pins (TA 1625). I have the (heavy) Sealed Power forged pistons and wanted to use those TA lightweight pins bring the recip weight back down close to stock. TA catalog lists the lightweight pin specs as 1.000" OD x 3.51"5 long with a weight of 188g. Does anyone know of an alternative source for these or similar lightweight pins with stock length and dia?
How many grams are you trying to remove? (I forget the difference between the two) Might be other easy ways to accomplish that.
The forged pistons weigh 765 g. The stocker I weighed was 726 g. So if I can make up 30-40 g that would be ideal.
Another pin with the correct diameter is the Wiseco S614 that weighs 163 g. However it is only 2.93 long whereas the pin bore span is 3.5" on the SP/TRW pistons. That would leave the ends of the pin 0.29" short on each end of the bore if the pin was centered, which could be a concern. The bore lands are 1.03" wide on each side, so still about 0.7" of bore engagement with the shorter pin. Anybody ever run the Wiseco S614 pins in the SP/TRW forged pistons?
If you were within 24 grams or so total bob weight, that would be roughly 1%, so think about the formula and where that comes from.
You can have custom pins made. Different lengths and thicknesses.Even tapered bores that are thicker in the center and thinner on the ends,to save weight.